U.S. patent number 4,526,423 [Application Number 06/501,113] was granted by the patent office on 1985-07-02 for back brace for director's chair.
Invention is credited to Charles I. Meinershagen, Susan G. Weale.
United States Patent |
4,526,423 |
Meinershagen , et
al. |
July 2, 1985 |
Back brace for director's chair
Abstract
A simple one-piece brace (20) provides rigidity to the vertical
back of a director's chair (10). The brace consists of a curved
length of heavy steel wire with a loop (22) on each end. Brace (20)
is made long enough so that each of its end loops (22) fits over
the respective two round uprights (12) of the chair. The brace is
installed by removing the canvas backpiece (14) of the chair and
fitting the end loops of the brace over the respective uprights and
then re-installing the backpiece. The brace is curved so that it
does not interfere with the back of a person sitting in the
chair.
Inventors: |
Meinershagen; Charles I.
(Redding, CA), Weale; Susan G. (Redding, CA) |
Family
ID: |
23992194 |
Appl.
No.: |
06/501,113 |
Filed: |
June 6, 1983 |
Current U.S.
Class: |
297/452.18;
248/188.91; 297/440.1; 297/463.1 |
Current CPC
Class: |
A47C
7/40 (20130101); A47C 4/38 (20130101) |
Current International
Class: |
A47C
7/40 (20060101); A47C 4/38 (20060101); A47C
4/00 (20060101); A47C 007/00 () |
Field of
Search: |
;297/440,441,444,445
;248/188.91 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Downey; Kenneth
Attorney, Agent or Firm: Pressman; David
Claims
I claim:
1. A brace for a collapsible chair of the type employing two
substantially parallel cantilevered members, said brace comprising
a wire member having a dimension substantially equal to the spacing
between said cantilevered members and containing a pair of loops at
the ends thereof for removable attachment around said respective
cantilevered members, said wire member having a curved
configuration which provides an arc which subtends a chord
extending in a straight line between said respective loops thereof,
said wire member being sufficiently rigid to hold said cantilevered
members apart when said chair is in use.
2. A brace of a collapsible chair of the type employing two
substantially parallel cantilevered members, said brace comprising
a wire member having a dimension substantially equal to the spacing
between said cantilevered members and containing means at the
extremities thereof in the direction of said dimension for
removable attachment to said cantilevered members, said means
comprising respective loops at the ends of said wire member for
engagement around said respective cantilevered members, said wire
member being sufficiently rigid to hold said cantilevered members
apart when said chair is in use.
3. A brace for a collapsible chair of the type employing two
substantially parallel cantilevered members, said brace comprising
a member having a dimension substantially equal to the spacing
between said cantilevered members and containing means at the
extremities thereof in the direction of said dimension for
removable attachment to said cantilevered members, said brace being
sufficiently rigid to hold said cantilevered members apart when
said chair is in use, said brace comprising a wire member, said
means comprising wire loops at the ends of said wire member for
engagement around said respective cantilevered members, said wire
member having a curved configuration which provides an arc which
subtends a chord extending in a straight line and between said
respective loops thereof.
Description
BACKGROUND
1. Field of Invention
This invention relates generally to chairs, particularly to an
improvement for a collapsible chair of the director's type.
2. Prior Art
Director's chairs have been widely used for many years and are most
commonly made of wooden structural members and some type of fabric
or canvas for the seat and back rest portions. These chairs come in
many particular styles, shapes, and sizes, ranging from low profile
lounge chairs to high, narrow bar chairs. While such director's
chairs have been very popular primarily due to their styling,
simplicity, comfort, and ease of storage, they have one major
shortcoming: a lack of structural integrity in the vertical members
of said chair.
In particular, long-term use of the director's chair has proven, in
the past, to be destructive to the glued and/or screwed wooden
joints that hold the vertical back members to the overall frame of
the chair. This has allowed the vertical members to loosen and lean
inward, toward each other, whenever a person sits in the chair,
making the chair both uncomfortable and unsafe.
OBJECTS AND ADVANTAGES OF THE INVENTION
One object of the invention is to provide a means for improving the
structural integrity of rigidity of a director's chair. Other
objects are to provide a means for enhancing the strength and
rigidity of such a chair without interfering with its advantages of
collapsibility, ease of storage, shape, comfort, styling, and
without necessitating any change in the structure, style, color,
collapsibility, or stability of the chair. Further objects are to
provide such means in which brace can be made of a variety of
materials which allow brace to conform to a person's back curvature
and thus be comfortable. Still further objects and advantages will
become apparent from a consideration of the ensuing description,
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a typical director's chair with the
the improvement of the present invention in place.
FIG. 2 is a close-up exploded perspective view of the chair with
the improvement of the invention illustrating the number of
installation.
DESCRIPTION OF THE INVENTION
As shown in the drawings, a director's chair comprises a
conventional hinged and pivotably interconnected frame assembly 10.
Frame assembly 10 includes two cantilevered vertical members or
uprights 12 which support a flexible canvas backpiece 14. Backpiece
14 comprises a web part with two parallel end loops or tubes 16
(best seen in FIG. 2) which telescope or slide over uprights 12 and
which come to rest or are stopped by widened portions, or the arm
members 24, or circumferential ledges 18 of uprights 12. Frame 10
is normally collapsed or folded easily to a compact arrangement by
removing flexible backpiece 14 and folding side vertical members 12
down laterally and collapsing frame 10 by laterally closing the
hinged and pivoted interconnecting diagonal legs.
In use, the two cantilevered vertical members 12 are the sole
support for backpiece 14 that stretches between members 12. When a
person is sitting in the director's chair and applying normal back
pressure to backpiece 14, considerable inward force is applied to
members 12. This inward force causes members 12 to lean toward each
other, causing discomfort to the person sitting in the chair. This
inward lean of members 12 is most pronounced after years of
continuous use; however, it is often evident even when the chair is
new.
In accordance with the present invention, the foregoing
disadvantages are overcome by a brace 20 which is installed (FIG.
2) on uprights 12 by removing canvas backpiece 14 (if it is not
already removed) and then fitting end loops 22 of brace 20 over
uprights 12 until they rest on ledges 18 or horizontal arm members
24. In the example shown in the drawings, brace 20 is constructed
in one piece of 9.5 mm (0.675 inch) diameter round steel wire.
Brace 20 has a length of 57.2 cm (22.5 inches) a curve radius of 61
cm (24 inches), and loop 22 at each end has an inside diameter of
28.6 mm (1.125 inches). Brace 20 thus has a curved configuration
which provides an arc which subtends a chord extending in a
straight line between uprights 12. The overall length of brace 20
and the diameter of loops 22 can be varied to fit the size of the
particular director's chair on which it is to be used. The distance
between the centers of the vertical members 12 typically range from
45.7 cm (18 inches) to 53.3 cm (21 inches) on director's chairs.
The diameter of vertical members 12 varies from 2.5 cm (1 inch) to
3.2 cm (1.25 inches).
After brace 20 is installed, backpiece 14 is simply placed in its
normal position by fitting its end loops 16 over uprights 12 as
indicated, whereupon loops 16 will rest on loops 22 of brace 20, in
lieu of on ledges 18.
With brace 20 and backpiece 15 in place (FIG. 1), the structural
integrity and rigidity of the vertical members 12 is significantly
enhanced. The parallelism of members 12 is mostly maintained even
while a person sitting in the chair is exerting back pressure on
backpiece 14.
While brace 20 is shown with a round cross-section, it can be made
of oval, rectangular, or even flattened stock. Brace 20 also can be
constructed either of plastic, fiberglass, or any other rigid,
semi-rigid, or semi-flexible material, or a combination of such
materials; brace 20 need merely be stiff enough to hold uprights 12
apart in normal use. In practice, a brace of 57.2 cm (22.5 inches)
long should not compress more than about 2.54 cm (1 inch) in
distance between end loops when a lateral force of 6.8 kg (15 lb)
is applied to the center of the brace, which is approximately
equivalent to the force resulting from a person leaning backward in
a chair. The flexibility of the material used will render the brace
more easily adaptable to a wider range of sizes of director's
chairs while maintaining both the structural integrity and comfort
for the user.
It is thus seen that brace 20 completely overcomes the disadvantage
of director's chairs whereby the back uprights thereof tend to lean
together. This is done with an economical, reliable,
easy-to-install addition which does not interfere with the styling,
collapsibility, portability, storability, or comfort of the chair,
or its adaptability to persons of various physical sizes.
While the above description contains many specificities, these
should not be construed as limitations on the scope of the
invention, but rather as an exemplification of one preferred
embodiment thereof. Accordingly, the full scope of the invention
should be determined not by the examples given, but by the appended
claims and their legal equivalents.
* * * * *